EN ISO 18674-1:2015

Geotechnical investigation and testing - Geotechnical monitoring by field instrumentation - Part 1: General rules (ISO 18674-1:2015)

ISO 18674-1:2015 lays out the general rules for the performance monitoring of the ground, of structures interacting with the ground, of geotechnical fills, and of geotechnical works.
Specifically, it applies to field instrumentation and measurements carried out: in connection with site investigations of soils and rocks, in connection with Observational Design procedures, in connection with the performance of geotechnical structures before, during, and after construction, for ground behaviour evaluation, e.g. unstable slopes, consolidation etc., for the proof or follow-up of a new equilibrium within the ground, after disturbance of its natural state by construction measures (e.g. foundation loads, excavation of soil, tunnelling), for the proof or follow-up of the stability, serviceability, and safety of structures and operations which might be influenced by geotechnical construction, for perpetuation of evidence, and for the evaluation and control of geotechnical works.

Geotechnische Erkundung und Untersuchung - Geotechnische Messungen - Teil 1: Allgemeine Regeln (ISO 18674-1:2015)

Die vorliegende Norm gilt für die Leistungsüberwachung von Baugrund, Bauwerken, die mit dem Baugrund in Wechselwirkung stehen, und geotechnische Anlagen.
Im Besonderen gilt diese Norm für die Geräteausrüstung für Feldmessungen (Feldinstrumentation) und Messungen, die durchgeführt werden
   in Verbindung mit Standorterkundungen von Böden und Fels nach EN 1997 2;
   in Verbindung mit der Beobachtungsmethode bei der Planung nach EN 1997 1;
   zur Bewertung des Verhaltens des Baugrunds, z. B. instabile Böschungen, Konsolidation usw.;
   zum Nachweis oder zur Folgeprüfung eines neuen Gleichgewichts im Baugrund nach einer Störung des natürlichen Zustands durch Baumaßnahmen (z. B. Fundamentlasten, Bodenaushub, Tunnelbau);
   zum Nachweis oder Folgeprüfung der Stabilität (Standsicherheit), Gebrauchstauglichkeit und Sicherheit von baulichen Anlagen, die möglicherweise durch geotechnische Anlagen beeinflusst werden;
   zur Beweissicherung;
   zur Bewertung und Lenkung geotechnischer Arbeiten.

Reconnaissance et essais géotechniques - Surveillance géotechnique par instrumentation in situ - Partie 1: Règles générales (ISO 18674-1:2015)

L'ISO 18674-1:2015 établit les règles générales d'exécution de la surveillance du sol, des structures interagissant avec le sol, des remblais géotechniques et des travaux géotechniques.
Elle s'applique spécifiquement à l'instrumentation déployée sur le terrain et aux mesurages réalisés : dans le cadre d'investigations in situ sur des sols et des roches; dans le cadre de la méthode observationnelle; dans le cadre de la performance des structures avant, pendant et après construction; pour l'évaluation du comportement des terrains, par exemple les pentes instables, les phénomènes de consolidation, etc.; pour la preuve ou le suivi d'un nouvel équilibre dans le terrain, après une perturbation de son état naturel par des mesures de construction (par exemple charges dues aux fondations, excavation de sol, creusement de tunnels); pour la preuve ou le suivi de la stabilité, de l'aptitude au service et de la sécurité des structures pouvant être influencées par les travaux géotechniques; pour la perpétuation des preuves; et pour l'évaluation et le contrôle des travaux géotechniques.

Geotehnično preiskovanje in preskušanje - Geotehnične meritve - 1. del: Splošna pravila (ISO 18674-1:2015)

Ta standard velja za meritve tal, struktur v povezavi s tlemi in geotehnična dela. Ta standard še zlasti velja za terenske instrumente in meritve v povezavi s preiskovanjem zemljin in kamnin v skladu s standardom EN 1997-2 v povezavi s postopkom opazovalnega projektiranja (Observational Design) v skladu s standardom EN 1997-1: za oceno vedenja tal, npr. nestabilnih pobočij, konsolidacijo itd. ali dokaz ali spremljanje novega ravnotežja tal po motnjah njihovega naravnega stanja z gradbenimi ukrepi (npr. obremenitve zaradi temeljenja, izkopa zemlje, gradnje predora); za dokaz ali spremljanje stabilnosti, uporabnosti in varnosti struktur, na katere lahko vplivajo geotehnične strukture; za ohranjanje dokazov; za ovrednotenje in nadzor geotehničnih del.

General Information

• Status: Published
• Publication Date: 19-May-2015
• Withdrawal Date: 29-Nov-2015
• ICS: 13.080.20 - Physical properties of soils
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: CEN/TC 341 - Geotechnical Investigation and Testing
• Drafting Committee: CEN/TC 341 - Geotechnical Investigation and Testing
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 20-May-2015
• Due Date: 12-Nov-2015
• Completion Date: 20-May-2015
• Ref Project: SIST EN ISO 18674-1:2015 - Geotechnical investigation and testing - Geotechnical monitoring by field instrumentation - Part 1: General rules (ISO 18674-1:2015)

Overview

EN ISO 18674-1:2015 - Geotechnical investigation and testing - Geotechnical monitoring by field instrumentation - Part 1: General rules - defines the general rules and framework for geotechnical monitoring using field instrumentation. Adopted by CEN, this standard sets out the scope, terminology, project requirements and high‑level procedures for performance monitoring of the ground, structures interacting with the ground, geotechnical fills and geotechnical works before, during and after construction.

The standard applies to monitoring in connection with:

• site investigations,
• Observational Design procedures,
• evaluation of ground behaviour (e.g. unstable slopes, consolidation),
• proof or follow‑up of new equilibrium after disturbance (foundation loading, excavation, tunnelling), and
• verification of stability, serviceability and safety, including perpetuation of evidence and control of works.

Key Topics and Requirements

• Terms and symbols: unified vocabulary for geotechnical monitoring (aligned with ISO/IEC Guide 99).
• Principal requirements: objectives of monitoring linked to design and safety decisions, inclusion in Observational Design.
• Monitoring system design: robustness, redundancy, stability of sensor signals, and consideration of influencing factors.
• Installation & measurement practice: location of measuring points (surface, interfaces, inside media), borehole measurements and field measurement methods.
• Quality assurance: function checks, calibration, geodetic measurements and safety requirements.
• Data management: processing, verification and reporting (installation reports and monitoring reports).
• Annexes: minimum content for instrument data sheets, examples of instruments and commonly used monitoring methods, and guidance on key geotechnical parameters.

Applications and Users

Who uses EN ISO 18674-1:

• Geotechnical engineers and consultants
• Site investigation teams and instrumentation specialists
• Contractors and construction monitoring teams
• Asset owners, project managers and safety officers
• Regulatory authorities and forensic investigators (perpetuation of evidence)

Practical applications:

• Designing and specifying field instrumentation and monitoring programmes
• Integrating monitoring into Observational Design and risk mitigation plans
• Tracking settlement, pore pressures, displacements, inclinations and other key parameters during excavation, tunnelling, foundation loading or slope stabilisation
• Providing accepted reporting formats and data-quality checks for construction acceptance and long‑term performance evaluation

Related Standards

EN ISO 18674-1 references and complements:

• ISO 14688-1 (soil identification/description)
• ISO 14689-1 (rock identification/description)
• ISO 22475-1 (sampling and groundwater measurement principles)
• ISO/IEC Guide 99 (metrology vocabulary)
• IEC 60529 (IP code for enclosures)

EN ISO 18674 is a series - Part 2 (extensometers) is published or in preparation and further parts cover inclinometers, piezometers, pressure cells, load cells and other sensor types.

Keywords: geotechnical monitoring, field instrumentation, ISO 18674-1, monitoring system design, observational design, geotechnical parameters.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2015
*HRWHKQLþQRSUHLVNRYDQMHLQSUHVNXãDQMH*HRWHKQLþQHPHULWYHGHO6SORãQD
SUDYLOD,62
Geotechnical investigation and testing - Geotechnical monitoring by field instrumentation
- Part 1: General rules (ISO 18674-1:2015)
Geotechnische Erkundung und Untersuchung - Geotechnische Messungen - Teil 1:
Allgemeine Regeln (ISO 18674-1:2015)
Reconnaissance et essais géotechniques - Surveillance géotechnique par
instrumentation in situ - Partie 1: Règles générales (ISO 18674-1:2015)
Ta slovenski standard je istoveten z: EN ISO 18674-1:2015
ICS:
93.020 Zemeljska dela. Izkopavanja. Earthworks. Excavations.
Gradnja temeljev. Dela pod Foundation construction.
zemljo Underground works
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 18674-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2015
ICS 13.080.20; 93.020
English Version
Geotechnical investigation and testing - Geotechnical monitoring
by field instrumentation - Part 1: General rules (ISO 18674-
1:2015)
Reconnaissance et essais géotechniques - Surveillance Geotechnische Erkundung und Untersuchung -
géotechnique par instrumentation in situ - Partie 1: Règles Geotechnische Messungen - Teil 1: Allgemeine Regeln
générales (ISO 18674-1:2015) (ISO 18674-1:2015)
This European Standard was approved by CEN on 30 April 2015.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18674-1:2015 E
worldwide for CEN national Members.

Contents Page
Foreword .3
Foreword
This document (EN ISO 18674-1:2015) has been prepared by Technical Committee ISO/TC 182
"Geotechnics" in collaboration with Technical Committee CEN/TC 341 “Geotechnical Investigation and
Testing” the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by November 2015, and conflicting national standards shall be withdrawn
at the latest by November 2015.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 18674-1:2015 has been approved by CEN as EN ISO 18674-1:2015 without any modification.

INTERNATIONAL ISO
STANDARD 18674-1
First edition
2015-05-15
Geotechnical investigation and
testing — Geotechnical monitoring by
field instrumentation —
Part 1:
General rules
Reconnaissance et essais géotechniques — Surveillance géotechnique
par instrumentation in situ —
Partie 1: Règles générales
Reference number
ISO 18674-1:2015(E)
©
ISO 2015
ISO 18674-1:2015(E)
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

ISO 18674-1:2015(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and symbols . 2
3.1 Terms . 2
3.2 Symbols . 4
4 Principal requirements . 5
4.1 Geotechnical monitoring in connection with geotechnical design . 5
4.2 Geotechnical monitoring in connection with specific questions . 5
4.3 Requirements of a geotechnical monitoring project . 5
4.4 Geodetic measurements . 6
4.5 Safety requirements . 6
5 Requirements of a geotechnical monitoring system . 6
5.1 General . 6
5.2 Robustness . 7
5.3 Influencing factors . 7
5.4 Redundancy . 7
5.5 Stability of sensor signal . 7
5.6 Function check and calibration . 8
6 Location of measuring points and geotechnical parameters . 8
6.1 Location of measuring points . 8
6.1.1 The measuring points can be located at free surfaces, at the interface
between any two media, or inside of a medium. . 8
6.2 Measurement and monitoring of geotechnical parameters . 8
7 Carrying out the measurements . 9
8 Data processing and verification . 9
9 Reporting .10
9.1 Installation report .10
9.2 Monitoring report .11
Annex A (normative) Minimum requirements on content of instrument data sheets .13
Annex B (normative) Geotechnical measurements in boreholes .14
Annex C (informative) Field measurements in connection with the design and construction
of geotechnical structures .17
Annex D (informative) Measurement and monitoring of geotechnical key parameters .19
Annex E (informative) Types of instruments and monitoring methods commonly used.21
Bibliography .27
ISO 18674-1:2015(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
ISO 18674-1 was prepared by European Committee for Standardization (CEN) in collaboration with
ISO/TC 182, Geotechnics, Subcommittee SC 01, Geotechnical investigation and testing, in accordance with
the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
ISO 18674 consists of the following parts, under the general title Geotechnical investigation and testing
— Geotechnical monitoring by field instrumentation:
— Part 1: General rules
The following parts are under preparation:
— Part 2: Displacement measurements along a line: Extensometers
The following parts are planned:
— Part 3: Displacement measurements across a line: Inclinometers
— Part 4: Piezometers
— Part 5: Total pressure cells
— Part 6: Hydraulic settlement gauges
— Part 7: Strain gauges
— Part 8: Load cells
— Part 9: Geodetic monitoring instruments
— Part 10: Vibration monitoring instruments

NOTE For further information on geotechnical monitoring by field instrumentation, see References [1] to [7].
iv © ISO 2015 – All rights reserved

INTERNATIONAL STANDARD ISO 18674-1:2015(E)
Geotechnical investigation and testing — Geotechnical
monitoring by field instrumentation —
Part 1:
General rules
1 Scope
This part of ISO 18674 lays out the general rules for the performance monitoring of the ground, of
structures interacting with the ground, of geotechnical fills, and of geotechnical works.
NOTE ISO 18674 fulfils the requirements for general rules for the performance monitoring of the ground, of
structures interacting with the ground, of geotechnical fills, and of geotechnical works as part of the geotechnical
[8] [9]
investigation and testing according to EN 1997-1 and EN 1997-2 .
Specifically, this part of ISO 18674 applies to field instrumentation and measurements carried out
— in connection with site investigations of soils and rocks,
— in connection with Observational Design procedures,
— in connection with the performance of geotechnical structures before, during, and after construction,
— for ground behaviour evaluation, e.g. unstable slopes, consolidation etc.,
— for the proof or follow-up of a new equilibrium within the ground, after disturbance of its natural
state by construction measures (e.g. foundation loads, excavation of soil, tunnelling),
— for the proof or follow-up of the stability, serviceability, and safety of structures and operations
which might be influenced by geotechnical construction,
— for perpetuation of evidence, and
— for the evaluation and control of geotechnical works.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 14688-1, Geotechnical investigation and testing — Identification and classification of soil — Part 1:
Identification and description
ISO 14689-1, Geotechnical investigation and testing — Identification and classification of rock — Part 1:
Identification and description
ISO 22475-1, Geotechnical investigation and testing — Sampling methods and groundwater measurements —
Part 1: Technical principles for execution
ISO/IEC Guide 99:2007, International vocabulary of metrology — Basic and general concepts and
associated terms (VIM)
IEC 60529, Degrees of protection provided by enclosures (IP Code)
ISO 18674-1:2015(E)
3 Terms and symbols
3.1 Terms
For the purposes of this document, the terms and definitions given in ISO/IEC Guide 99:2007 and the
following apply.
3.1.1
geotechnical monitoring
observation of the ground behaviour and/or performance of geotechnical structures before, during,
and/or after construction
Note 1 to entry: Geotechnical monitoring is an integral part of the Observational Design procedure (see
EN 1997–1: 2004).
Note 2 to entry: Geotechnical monitoring is based on field observation, including construction site inspection.
3.1.2
field instrument
measuring tool to assist geotechnical monitoring
Note 1 to entry: Monitoring by field instruments comprises the measurement of physical parameters, in particular,
the change of the parameter values.
3.1.3
geotechnical key parameter
physical parameter indicative of the geotechnical issue under consideration and subject to
geotechnical monitoring
EXAMPLE Displacement (absolute or relative), strain, inclination, stress, pore pressure, earth pressure,
force, velocity, acceleration, temperature.
3.1.4
geotechnical monitoring project
entirety of aspects and processes which, in a specific project, are relevant for geotechnical monitoring
Note 1 to entry: Includes planning, risk assessment, specifying, procurement, delivery, and installation of a
project-specific monitoring system and collecting, processing, evaluating, and reporting of the monitoring data.
3.1.5
geotechnical monitoring concept
preliminary plan for the measurement of geotechnical key parameters developed within the conceptual
design phase, identifying specific objectives such as risk mitigation to be addressed by monitoring, thereby
considering type of measurement, measuring locations, and schedule(s) for carrying out the measurement
3.1.6
geotechnical monitoring plan
advancement of the monitoring concept within the specification design phase
3.1.7
geotechnical monitoring system
hardware and software to provide field data
Note 1 to entry: Includes instruments signal, transmission (e.g. electric cables), data acquisition, and auxiliary units.
Note 2 to entry: The performance (e.g. the accuracy, stability, precision) of the geotechnical monitoring system
will not necessarily be identical to the performances of the system components.
3.1.8
geotechnical monitoring programme
entirety of those components of a monitoring project which can be systematically planned, consisting of
a monitoring plan and monitoring system
2 © ISO 2015 – All rights reserved

ISO 18674-1:2015(E)
3.1.9
commissioning
demonstration and acceptance of the correct functioning of an installed monitoring system
Note 1 to entry: The commissioning criteria are commonly defined in the monitoring plan.
3.1.10
instrument data sheet
manufacturer’s document containing instrument technical specifications
3.1.11
initial measurement
first measurement after installation (see Figure 1)
3.1.12
zero measurement
measurement carried out after stabilization of installation effects (see Figure 1)
Note 1 to entry: The zero measurement is often taken as reference for subsequent measurements, as it is commonly
related to local space and time coordinates.
Note 2 to entry: The zero measurement is commonly carried out with increased measuring effort, e.g. repetition
of measurements, to provide a reliable datum for subsequent measurements.
Y
X
45 67
Key
1 initial measurement
2 zero measurement
3 reference measurement
4 installation period
5 stabilization period
6 period of baseline measurements
7 construction period
X time
Y reading
Figure 1 — Definition of distinct measuring points during a geotechnical monitoring project in
the period up to and including the construction phase
3.1.13
baseline measurements
measurements carried out, subsequent to the zero measurement, over a period of time before any
construction starts, to help in the definition of changes that occur from causes other than construction
EXAMPLE Seasonal changes in groundwater levels, tidal and moisture content changes, climatic changes
such as temperature, and incidence of sunlight.
ISO 18674-1:2015(E)
3.1.14
reference measurement
measurement which serves as reference base for previous and subsequent measurements
Note 1 to entry: The reference measurement is also known as datum measurement.
Note 2 to entry: A new reference measurement is often used for a new construction phase.
Note 3 to entry: The reference measurement is often derived from several measurements.
3.1.15
value change measurement
difference between a measurement and the reference measurement
3.1.16
point measurement
measurement of a physical parameter at a point
EXAMPLE Displacement of a measuring point; force of an anchor at its head; stress state in the ground;
porewater pressure in an embankment; water discharge rate at the downstream toe of a dam.
3.1.17
line measurement
measurement of a physical parameter along a line
EXAMPLE Inclinometer measuring survey of a borehole.
3.2 Symbols
For the purpose of this document, the symbols of Table 1 apply.
Table 1 — Symbols
Symbol Name Unit
d borehole diameter m
i number of measurement, measurement direction, or measuring point -
l distance m
u, v, w displacement component in x-, y-, z- direction, respectively m
u porewater pressure Pa
x, y, z local coordinates m
z piezometric level m
w
α angle, inclination Degree or mm/m
ε strain normal to measuring plane -
n
ε ε ε normal strain with reference to borehole coordinates -
x y z
γ γ γ shear strain with reference to borehole coordinates -
xy yz zx
σ σ σ principal stress Pa
1 2 3
σ normal stress with reference to measuring plane Pa
n
σ σ σ normal stress components with reference to borehole coordinates Pa
x y z
τ τ τ shear stress components with reference to borehole coordinates Pa
xy yz zx
NOTE Symbols with more than one meaning (e.g. u) are distinguishable in the context of their use.
4 © ISO 2015 – All rights reserved

ISO 18674-1:2015(E)
4 Principal requirements
4.1 Geotechnical monitoring in connection with geotechnical design
Geotechnical monitoring shall be designed, implemented, and evaluated in connection with the
geotechnical design.
NOTE Figure C.1 shows the position of geotechnical monitoring in connection with the design and the
construction of geotechnical structures; see also “observational method” in EN 1997–1: 2004, 2.7.
4.2 Geotechnical monitoring in connection with specific questions
Each geotechnical monitoring project shall be based on at least one specific question that is to be
answered. The question shall be formulated at the start of the monitoring project and actualized
throughout the project with the aid of information from the measurements.
NOTE Monitoring of construction procedures and long-term monitoring of existing safety-sensitive
structures are included.
4.3 Requirements of a geotechnical monitoring project
4.3.1 In a geotechnical monitoring project, all items as defined in 3.1.4 shall be considered in the
sequence described in 4.3.2 to 4.3.7.
4.3.2 Within the initiation and preliminary design phase, reference shall be made to the geotechnical
issue to be addressed. The key parameters shall be identified and their expected range estimated. The
accuracy and the uncertainty with which the key parameters are to be measured and their geotechnically
tolerable limits shall be specified.
4.3.3 Within the conceptual design phase, a concept shall be developed on how to measure the key
parameters of the geotechnical issue under consideration.
NOTE Aspects for consideration are the principal type of the instruments, frequency of measurements,
redundancy in the system, the anticipated operation time of the monitoring system, and potential risks associated
with monitoring.
4.3.4 Within the specification design phase, the monitoring concept shall be refined and transferred
into a comprehensive monitoring programme. Aspects which shall be considered are the instrument
selection based on instrument data sheets (Annex A) together with expected field performance and the
specification of the instrument installation procedure.
NOTE 1 The monitoring plan includes the specification of the measuring procedure, the location of the
monitoring points, the monitoring schedule, and the type of data collection (manual reading or data logging with
or without remote data access).
NOTE 2 The measuring procedure might encompass the measuring principle (physical base of the measurement,
e.g. vibrating wire principle) and of the measuring method (e.g. compensation method, digital/analogue method).
NOTE 3 Field instruments comprise a large variety of sensors with different measuring principles which all
have their specific advantages and disadvantages depending on the type of application. Examples of sensors with
different measuring principles are vibrating wire, current-loop, inductive, capacitive, resistance strain gauge, and
fibre-optical sensors.
4.3.5 Within the installation and data collection phases, it shall be ensured that
— the instrument system is installed as early as possible prior to construction for baseline
measurements (see Figure 1),
— the installation is carried out in such a way as to achieve good conformance of the measuring instruments,
ISO 18674-1:2015(E)
NOTE Good conformance is associated with only insignificant, if any, alterations of the measured values by
the presence of the instrument
— the instruments are operated and handled in accordance with the manufacturer’s instructions, and
— the monitoring system is routinely inspected and adequately protected from site works.
4.3.6 Within the data processing, evaluation, and reporting phase, attention shall be paid to the fact
that the monitoring data are often affected by instrument, installation, and environmental effects (see
5.3). In the evaluation process, plausibility checks of the monitoring data shall be carried out. Checking
shall include instrument, as well as geotechnical aspects (see 8.5).
4.3.7 The monitoring results shall be evaluated in respect to the geotechnical issue under consideration.
4.4 Geodetic measurements
For the support, evaluation, and control of geotechnical measurements, reference shall be made to
geodetic measurements if applicable.
NOTE 1 See ISO 18674-9.
NOTE 2 For comparison of geotechnical and geodetic measurements, see Table C.1.
4.5 Safety requirements
National and site safety regulations shall be followed.
EXAMPLES Regulations for:
— personal health and safety equipment;
— clean air if working in confined spaces;
— ensuring the safety of the measuring system and its components.
5 Requirements of a geotechnical monitoring system
5.1 General
5.1.1 Geotechnical monitoring systems are subject to specific conditions, which shall be accounted for in
the monitoring programme and evaluation of the monitoring data. These conditions include the following:
— mechanical, hydro-mechanical, or thermo-mechanical interaction between critical components of
the geotechnical measuring system (e.g. sensors, measuring lines) and the surrounding medium in
which the components are embedded;
— environmental conditions (e.g. aggressive groundwater and gases; high ground pressure; electro-
magnetic disturbance) which might affect the embedded components;
— vulnerability of the data communication of the monitoring system (e.g. long measuring lines, often
passing through construction zones).
5.1.2 The sign conventions and units shall be clearly stated and adhered to.
5.1.3 Requirements 5.2 to 5.6 shall be documented.
NOTE Manufacturers’ documentation, e.g. instrument data sheets (see Annex A), is to provide a basis to make
an informed choice of the instruments.
6 © ISO 2015 – All rights reserved

ISO 18674-1:2015(E)
5.2 Robustness
5.2.1 The components of the system shall be robust enough to effectively perform their individual
functions over the design lifetime of the system, despite environmental and construction conditions.
NOTE This requirement relates to the material used (e.g. quality of the measuring cable, corrosion resistance
of sensors), the type of construction of the installed units, and to the safety of the entire monitoring system, e.g.
towards o
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